‘For whatever reason, it felt like I just needed to check back in with this guy,’ Turow says of his new novel ‘Innocent,’ the sequel to his 1987 bestseller.

Literary empires have to start somewhere, and Scott Turow's began 23 years ago with the creation of an unusually trusting prosecutor named Rusty Sabich, whose affair with a somewhat pathological colleague made him the prime suspect after she was found bound, naked and dead.

Sabich, of course, was innocent — not much of a murder-mystery if the protagonist is guilty. But the twisting plot Turow hatched for that debut novel, "Presumed Innocent," kept readers thinking and dissecting long after they finished the book.

And it helped make Turow a rich man. In a harbinger of Hollywood deals to come, Sydney Pollack bought the film rights for $1 million before the book even came out in August 1987. The paperback rights quickly sold for $3 million — a record for a debut novel.

Yet "Presumed Innocent" also propelled what had been a marginal genre — the legal thriller — to the top of the bestseller list, paving the way for successors such as John Grisham.

And now, 23 years later, Sabich is back in full as the main character in "Innocent" (Grand Central: 408 pp., $27.99), Turow's latest. Another body has been found, and this time the victim is Sabich's wife. While Sabich's innocence is again presumed, it's not so clear that he really is.

"When you write books, something grabs at you, and it's often years later that you understand what it is you're trying to do, and what it is that's moving you," Turow says. "For whatever reason, it felt like I just needed to check back in with this guy."

The new book continues to explore the geography on which Turow's other eight novels took place — the fictional Kindle County. The terrain bears a striking resemblance to Turow's native Cook County, with a nameless city somewhat smaller than Chicago as its urban center and the hapless Trappers professional baseball team to match the star-crossed Chicago Cubs.

Yet the strength of Turow's books lies less in place and plot than in the power of the storytelling, says literature professor Katherine Min, who includes "Presumed Innocent" in her Murder and Imagination course at the University of North Carolina in Asheville.

"When I read ‘Presumed Innocent,' I was immediately struck by how textured and multidimensional his characters were," she says. Even the supporting characters "are all well-drawn and psychologically complex. It's a ripping good story with a fabulous twist, sure, but it's the characters and the quality of the writing that mark Turow as more than just another legal thriller writer."

Turow, a former prosecutor, sees himself as the lucky beneficiary of timing.

"I would love to believe that I totally reinvented the world, but I don't," says Turow, who still lives near Chicago, where he practices law. "There were a lot of social forces at work that I think made people intensely curious about the law. Look at the wide range of movies and books and TV shows about the law you ended up with —Court TV, an entire television [channel] devoted to trials. For me to pretend that I created all of that — even my vanity doesn't run that far."

He ascribes that public embrace of fictional lawyers to the "increasingly pivotal role in the society" played by the law, beginning with Watergate and the confirmation that "even the president of the United States can be prosecuted."

"There was this sort of cascade that brings us to the point where the parish priest can also be prosecuted," Turow says. "So the law grew in importance. It grew as a vehicle of social reform. You have O.J. [Simpson], and ‘L.A. Law' was on television. So there was a lot going on."

And, yes, people hate lawyers, but Turow says it's not a complete rejection: "People hate the other guy's lawyer. They tend to be OK with their own lawyer."

The new novel picks up more than 20 years along in Sabich's career. The sequel began, Turow says, with an image, and an assignment to write a serialized novella for the Sunday New York Times Magazine. The story, published in 2006 as the novella "Limitations," centered on an appeals court judge — George Mason, a colleague of Sabich's — stumbling over a rape case with echoes from his own past.

"I had this Post-it note that had been sitting on my desk for days which said that ‘A man is sitting on a bed in which the body of a dead woman lies,' " Turow says. "It was something I was going to write down and keep in a notebook. I suddenly turned to it one day, just at the beginning of thinking about ‘Limitations,' and said, wait a minute, that's Rusty Sabich sitting on the bed." Turow had planned to focus on Sabich in "Limitations" but scaled it back. When the novella was done, he turned to "Innocent," placing Sabich on center stage again.